Mechanical touch fastening involves the engagement of a field of fastening elements, such as hooks, with a field of mating elements, such as fibers of a fabric. Although mechanical engagement may be said to happen between individual fastening elements, which may themselves be extremely small, the overall characteristics of the fastening are described in terms of the aggregate of a great number of individual engagements across a broad area. Such fastening systems are generally designed, therefore, with an eye to statistical engagement, as it is not generally feasible to accurately position corresponding hooks and fibers to ensure their mutual engagement.
In many touch fastening systems the positioning of the fibers, in particular, is relatively random or statistical, even when such fibers are of a fabric formed by weaving or knitting. In non-woven materials fiber positioning and orientation is even more random.
The hook side of touch fastening systems may be formed so as to have a fairly regular and controlled positioning and orientation of male fastening elements, such as by molding them in a regular pattern of rows and columns as part of a fastener strip. In some other cases they are formed by severing or trimming loops extending from a woven fabric.
In generally available commercial touch fastening systems, the hook side of the fastening is manufactured as a strip or patch that carries the array of hooking elements and is then affixed to a surface to which something is to be releasably secured. In the manufacture of disposable diapers, for example, pre-formed fastening strips carrying arrays of male fastening elements are typically fixed to a material that forms a diaper tab that is, in turn, fixed to a diaper chassis. The fiber or loop side of the fastening system may be, in some cases, already available (such as in the form of the outer surface of a fibrous garment), or is supplied by securing a patch or strip of loop material manufactured specifically for certain touch fastening properties.
Improvements are continually sought for more efficient and adaptable ways to provide surface with fastening properties, and in the manufacture of fastening products.